The Type D plug is what happens when colonial powers move on but their infrastructure stays behind. The plug was Britain's pre-1947 standard, formalized under BS 546. When Britain replaced it with the safer Type G design, India and several other former colonies kept Type D rather than rebuilding their electrical systems.
This guide covers the design, the history, and where you'll meet Type D in 2026.
What Type D is
The Type D plug has three pins:
- Three round pins, 5 mm diameter, arranged in a triangular pattern
- The earth pin (centre, top) is the largest of the three
- The live and neutral pins (bottom corners) are equally sized
- Total current rating: 5 amps at 230-250 V
The socket has matching circular slots in the triangle pattern. Modern Type D sockets in India also accept Type C Europlugs because the pin spacing matches.
The 1930s British origin
Type D was Britain's primary consumer plug from the 1930s through 1947, defined under BS 546. The design solved several problems with earlier ungrounded plugs:
- Dedicated earth pin for grounded appliances
- Polarized design (the earth pin position fixed plug orientation)
- Round pins that were easier to manufacture than later flat-pin designs
- Multiple current ratings (2 A, 5 A, 15 A) in similar-looking but non-interchangeable sizes
By the 1940s, BS 546 was the dominant plug across Britain and its colonies. The 5 A variant was used for lighting and household electronics; the 15 A variant for high-current appliances; the 2 A variant for small radios and lamps.
The 1947 transition
After World War II, Britain decided to replace BS 546 with a newer design that solved several safety problems Type D couldn't address:
- No fuse in the plug (BS 546 relied on building-level circuit protection)
- Exposed live metal during partial insertion
- No socket shutters (foreign objects could be inserted)
- Multiple sizes of plugs and sockets required for different current ratings
The replacement, BS 1363 (Type G), addressed all of these. Britain phased out Type D for new construction starting in 1947 and the transition was complete by the 1970s.
India, Nepal, Sri Lanka, and several African former colonies kept Type D. The reason was economic: replacing millions of installed sockets was prohibitively expensive, especially in newly-independent countries with limited capital. Type G's marginal safety improvements weren't enough to justify the cost.
Where Type D is used today
India
The dominant standard, alongside Type M for high-current circuits. New Indian construction increasingly uses Type F Schuko in hybrid sockets, but Type D remains common.
Nepal
Same Type D as India, often in older buildings. Newer construction sometimes uses Type C Europlug sockets that accept Type D plugs.
Sri Lanka
Type D dominant. Some Type G in newer construction reflecting Sri Lanka's closer historical ties with the UK.
Bangladesh
Type D widely used. Type G is also present in some commercial buildings.
African Type D countries
Nigeria, Kenya, Tanzania, Uganda, and several others use Type D as a primary or secondary standard. The mix varies by country and by city; many African countries have both Type D and Schuko or Type G depending on building age.
Hong Kong and Singapore
Type D was historically used but both territories have transitioned to Type G. You may occasionally find Type D sockets in older buildings.
Type D's safety profile
Compared to modern plug designs:
- No in-plug fuse (relies on circuit-level protection)
- No sleeved pins (live metal exposed during insertion)
- No socket shutters (foreign objects can be inserted)
- Polarized but earth pin doesn't open shutters (no shutters to open)
The Type D failure modes are similar to other older designs. Modern Indian electrical codes mitigate some risks through circuit-level protection, but the plug itself is less safe than Type G or modern Schuko variants.
Practical implications for travelers
If you're traveling to India, Nepal, Sri Lanka, or other Type D countries:
- A Type D-capable adapter is essential
- Most universal adapters include Type D coverage, but verify in the spec
- Europlugs often fit Type D sockets (handy if you already have one)
- For grounded high-draw appliances, you'll need a separate Type M adapter for the higher-current circuits
If you're a Type D traveler heading abroad:
- Type D doesn't fit anywhere outside Type D countries
- A universal adapter for the destination is required
- For UK travel specifically, a Type D-to-Type G adapter is widely available
Type D vs other plug types
| Feature | Type D | Type G (UK) | Type M (India high-current) | Type B (US) |
|---|---|---|---|---|
| Pin count | 3 | 3 | 3 | 3 |
| Pin shape | Round | Rectangular | Round (larger) | Flat parallel |
| Earth pin size | Large (centre) | Largest (top, longest) | Largest (centre) | Round (bottom) |
| Current rating | 5 A | 13 A | 15 A | 15 A |
| Built-in fuse | No | Yes | No | No |
| Sleeved live pins | No | Yes | No | No |
| Socket shutters | No | Yes | No | No |
Type D is the simplest of the modern grounded plug designs and has the lowest current rating. The 5 A limit suits household electronics but not high-draw appliances, which is why Type M was developed as a companion standard for the same triangular pin layout at higher current.
The bottom line
Type D is a 1930s British plug that survived long after Britain itself replaced it. The design lives on across India, Nepal, Sri Lanka, Bangladesh, and parts of Africa as a legacy of colonial infrastructure that became too expensive to replace.
For travelers: ensure your universal adapter explicitly covers Type D. The plug works fine for low-draw devices but you may need a separate Type M adapter for higher-current appliances in some accommodations.